CVE-2025-39754

In the Linux kernel, the following vulnerability has been resolved:

mm/smaps: fix race between smaps_hugetlb_range and migration

smaps_hugetlb_range() handles the pte without holdling ptl, and may be

concurrenct with migration, leaing to BUG_ON in pfn_swap_entry_to_page().

The race is as follows.

smaps_hugetlb_range migrate_pages

huge_ptep_get

remove_migration_ptes

folio_unlock

pfn_swap_entry_folio

BUG_ON

To fix it, hold ptl lock in smaps_hugetlb_range().